summaryrefslogtreecommitdiffstats
path: root/drivers/pinctrl/aspeed/pinmux-aspeed.h
blob: f86739e800c321adc1fce9d71f785e3b4bc3965e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
/* SPDX-License-Identifier: GPL-2.0-or-later */
/* Copyright (C) 2019 IBM Corp.  */

#ifndef ASPEED_PINMUX_H
#define ASPEED_PINMUX_H

#include <linux/regmap.h>
#include <stdbool.h>

/*
 * The ASPEED SoCs provide typically more than 200 pins for GPIO and other
 * functions. The SoC function enabled on a pin is determined on a priority
 * basis where a given pin can provide a number of different signal types.
 *
 * The signal active on a pin is described by both a priority level and
 * compound logical expressions involving multiple operators, registers and
 * bits. Some difficulty arises as the pin's function bit masks for each
 * priority level are frequently not the same (i.e. cannot just flip a bit to
 * change from a high to low priority signal), or even in the same register.
 * Further, not all signals can be unmuxed, as some expressions depend on
 * values in the hardware strapping register (which may be treated as
 * read-only).
 *
 * SoC Multi-function Pin Expression Examples
 * ------------------------------------------
 *
 * Here are some sample mux configurations from the AST2400 and AST2500
 * datasheets to illustrate the corner cases, roughly in order of least to most
 * corner. The signal priorities are in decending order from P0 (highest).
 *
 * D6 is a pin with a single function (beside GPIO); a high priority signal
 * that participates in one function:
 *
 * Ball | Default | P0 Signal | P0 Expression               | P1 Signal | P1 Expression | Other
 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
 *  D6    GPIOA0    MAC1LINK    SCU80[0]=1                                                GPIOA0
 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
 *
 * C5 is a multi-signal pin (high and low priority signals). Here we touch
 * different registers for the different functions that enable each signal:
 *
 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
 *  C5    GPIOA4    SCL9        SCU90[22]=1                   TIMER5      SCU80[4]=1      GPIOA4
 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
 *
 * E19 is a single-signal pin with two functions that influence the active
 * signal. In this case both bits have the same meaning - enable a dedicated
 * LPC reset pin. However it's not always the case that the bits in the
 * OR-relationship have the same meaning.
 *
 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
 *  E19   GPIOB4    LPCRST#     SCU80[12]=1 | Strap[14]=1                                 GPIOB4
 * -----+---------+-----------+-----------------------------+-----------+---------------+----------
 *
 * For example, pin B19 has a low-priority signal that's enabled by two
 * distinct SoC functions: A specific SIOPBI bit in register SCUA4, and an ACPI
 * bit in the STRAP register. The ACPI bit configures signals on pins in
 * addition to B19. Both of the low priority functions as well as the high
 * priority function must be disabled for GPIOF1 to be used.
 *
 * Ball | Default | P0 Signal | P0 Expression                           | P1 Signal | P1 Expression                          | Other
 * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
 *  B19   GPIOF1    NDCD4       SCU80[25]=1                               SIOPBI#     SCUA4[12]=1 | Strap[19]=0                GPIOF1
 * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
 *
 * For pin E18, the SoC ANDs the expected state of three bits to determine the
 * pin's active signal:
 *
 * * SCU3C[3]: Enable external SOC reset function
 * * SCU80[15]: Enable SPICS1# or EXTRST# function pin
 * * SCU90[31]: Select SPI interface CS# output
 *
 * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
 *  E18   GPIOB7    EXTRST#     SCU3C[3]=1 & SCU80[15]=1 & SCU90[31]=0    SPICS1#     SCU3C[3]=1 & SCU80[15]=1 & SCU90[31]=1   GPIOB7
 * -----+---------+-----------+-----------------------------------------+-----------+----------------------------------------+----------
 *
 * (Bits SCU3C[3] and SCU80[15] appear to only be used in the expressions for
 * selecting the signals on pin E18)
 *
 * Pin T5 is a multi-signal pin with a more complex configuration:
 *
 * Ball | Default | P0 Signal | P0 Expression                | P1 Signal | P1 Expression | Other
 * -----+---------+-----------+------------------------------+-----------+---------------+----------
 *  T5    GPIOL1    VPIDE       SCU90[5:4]!=0 & SCU84[17]=1    NDCD1       SCU84[17]=1     GPIOL1
 * -----+---------+-----------+------------------------------+-----------+---------------+----------
 *
 * The high priority signal configuration is best thought of in terms of its
 * exploded form, with reference to the SCU90[5:4] bits:
 *
 * * SCU90[5:4]=00: disable
 * * SCU90[5:4]=01: 18 bits (R6/G6/B6) video mode.
 * * SCU90[5:4]=10: 24 bits (R8/G8/B8) video mode.
 * * SCU90[5:4]=11: 30 bits (R10/G10/B10) video mode.
 *
 * Re-writing:
 *
 * -----+---------+-----------+------------------------------+-----------+---------------+----------
 *  T5    GPIOL1    VPIDE      (SCU90[5:4]=1 & SCU84[17]=1)    NDCD1       SCU84[17]=1     GPIOL1
 *                             | (SCU90[5:4]=2 & SCU84[17]=1)
 *                             | (SCU90[5:4]=3 & SCU84[17]=1)
 * -----+---------+-----------+------------------------------+-----------+---------------+----------
 *
 * For reference the SCU84[17] bit configure the "UART1 NDCD1 or Video VPIDE
 * function pin", where the signal itself is determined by whether SCU94[5:4]
 * is disabled or in one of the 18, 24 or 30bit video modes.
 *
 * Other video-input-related pins require an explicit state in SCU90[5:4], e.g.
 * W1 and U5:
 *
 * -----+---------+-----------+------------------------------+-----------+---------------+----------
 *  W1    GPIOL6    VPIB0       SCU90[5:4]=3 & SCU84[22]=1     TXD1        SCU84[22]=1     GPIOL6
 *  U5    GPIOL7    VPIB1       SCU90[5:4]=3 & SCU84[23]=1     RXD1        SCU84[23]=1     GPIOL7
 * -----+---------+-----------+------------------------------+-----------+---------------+----------
 *
 * The examples of T5 and W1 are particularly fertile, as they also demonstrate
 * that despite operating as part of the video input bus each signal needs to
 * be enabled individually via it's own SCU84 (in the cases of T5 and W1)
 * register bit. This is a little crazy if the bus doesn't have optional
 * signals, but is used to decent effect with some of the UARTs where not all
 * signals are required. However, this isn't done consistently - UART1 is
 * enabled on a per-pin basis, and by contrast, all signals for UART6 are
 * enabled by a single bit.
 *
 * Further, the high and low priority signals listed in the table above share
 * a configuration bit. The VPI signals should operate in concert in a single
 * function, but the UART signals should retain the ability to be configured
 * independently. This pushes the implementation down the path of tagging a
 * signal's expressions with the function they participate in, rather than
 * defining masks affecting multiple signals per function. The latter approach
 * fails in this instance where applying the configuration for the UART pin of
 * interest will stomp on the state of other UART signals when disabling the
 * VPI functions on the current pin.
 *
 * Ball |  Default   | P0 Signal | P0 Expression             | P1 Signal | P1 Expression | Other
 * -----+------------+-----------+---------------------------+-----------+---------------+------------
 *  A12   RGMII1TXCK   GPIOT0      SCUA0[0]=1                  RMII1TXEN   Strap[6]=0      RGMII1TXCK
 *  B12   RGMII1TXCTL  GPIOT1      SCUA0[1]=1                  –           Strap[6]=0      RGMII1TXCTL
 * -----+------------+-----------+---------------------------+-----------+---------------+------------
 *
 * A12 demonstrates that the "Other" signal isn't always GPIO - in this case
 * GPIOT0 is a high-priority signal and RGMII1TXCK is Other. Thus, GPIO
 * should be treated like any other signal type with full function expression
 * requirements, and not assumed to be the default case. Separately, GPIOT0 and
 * GPIOT1's signal descriptor bits are distinct, therefore we must iterate all
 * pins in the function's group to disable the higher-priority signals such
 * that the signal for the function of interest is correctly enabled.
 *
 * Finally, three priority levels aren't always enough; the AST2500 brings with
 * it 18 pins of five priority levels, however the 18 pins only use three of
 * the five priority levels.
 *
 * Ultimately the requirement to control pins in the examples above drive the
 * design:
 *
 * * Pins provide signals according to functions activated in the mux
 *   configuration
 *
 * * Pins provide up to five signal types in a priority order
 *
 * * For priorities levels defined on a pin, each priority provides one signal
 *
 * * Enabling lower priority signals requires higher priority signals be
 *   disabled
 *
 * * A function represents a set of signals; functions are distinct if they
 *   do not share a subset of signals (and may be distinct if they are a
 *   strict subset).
 *
 * * Signals participate in one or more functions or groups
 *
 * * A function is described by an expression of one or more signal
 *   descriptors, which compare bit values in a register
 *
 * * A signal expression is the smallest set of signal descriptors whose
 *   comparisons must evaluate 'true' for a signal to be enabled on a pin.
 *
 * * A signal participating in a function is active on a pin if evaluating all
 *   signal descriptors in the pin's signal expression for the function yields
 *   a 'true' result
 *
 * * A signal at a given priority on a given pin is active if any of the
 *   functions in which the signal participates are active, and no higher
 *   priority signal on the pin is active
 *
 * * GPIO is configured per-pin
 *
 * And so:
 *
 * * To disable a signal, any function(s) activating the signal must be
 *   disabled
 *
 * * Each pin must know the signal expressions of functions in which it
 *   participates, for the purpose of enabling the Other function. This is done
 *   by deactivating all functions that activate higher priority signals on the
 *   pin.
 *
 * As a concrete example:
 *
 * * T5 provides three signals types: VPIDE, NDCD1 and GPIO
 *
 * * The VPIDE signal participates in 3 functions: VPI18, VPI24 and VPI30
 *
 * * The NDCD1 signal participates in just its own NDCD1 function
 *
 * * VPIDE is high priority, NDCD1 is low priority, and GPIOL1 is the least
 *   prioritised
 *
 * * The prerequisit for activating the NDCD1 signal is that the VPI18, VPI24
 *   and VPI30 functions all be disabled
 *
 * * Similarly, all of VPI18, VPI24, VPI30 and NDCD1 functions must be disabled
 *   to provide GPIOL6
 *
 * Considerations
 * --------------
 *
 * If pinctrl allows us to allocate a pin we can configure a function without
 * concern for the function of already allocated pins, if pin groups are
 * created with respect to the SoC functions in which they participate. This is
 * intuitive, but it did not feel obvious from the bit/pin relationships.
 *
 * Conversely, failing to allocate all pins in a group indicates some bits (as
 * well as pins) required for the group's configuration will already be in use,
 * likely in a way that's inconsistent with the requirements of the failed
 * group.
 *
 * Implementation
 * --------------
 *
 * Beyond the documentation below the various structures and helper macros that
 * allow the implementation to hang together are defined. The macros are fairly
 * dense, so below we walk through some raw examples of the configuration
 * tables in an effort to clarify the concepts.
 *
 * The complexity of configuring the mux combined with the scale of the pins
 * and functions was a concern, so the table design along with the macro jungle
 * is an attempt to address it. The rough principles of the approach are:
 *
 * 1. Use a data-driven solution rather than embedding state into code
 * 2. Minimise editing to the specifics of the given mux configuration
 * 3. Detect as many errors as possible at compile time
 *
 * Addressing point 3 leads to naming of symbols in terms of the four
 * properties associated with a given mux configuration: The pin, the signal,
 * the group and the function. In this way copy/paste errors cause duplicate
 * symbols to be defined, which prevents successful compilation. Failing to
 * properly parent the tables leads to unused symbol warnings, and use of
 * designated initialisers and additional warnings ensures that there are
 * no override errors in the pin, group and function arrays.
 *
 * Addressing point 2 drives the development of the macro jungle, as it
 * centralises the definition noise at the cost of taking some time to
 * understand.
 *
 * Here's a complete, concrete "pre-processed" example of the table structures
 * used to describe the D6 ball from the examples above:
 *
 * ```
 * static const struct aspeed_sig_desc sig_descs_MAC1LINK_MAC1LINK[] = {
 *     {
 *         .ip = ASPEED_IP_SCU,
 *         .reg = 0x80,
 *         .mask = BIT(0),
 *         .enable = 1,
 *         .disable = 0
 *     },
 * };
 *
 * static const struct aspeed_sig_expr sig_expr_MAC1LINK_MAC1LINK = {
 *     .signal = "MAC1LINK",
 *     .function = "MAC1LINK",
 *     .ndescs = ARRAY_SIZE(sig_descs_MAC1LINK_MAC1LINK),
 *     .descs = &(sig_descs_MAC1LINK_MAC1LINK)[0],
 * };
 *
 * static const struct aspeed_sig_expr *sig_exprs_MAC1LINK_MAC1LINK[] = {
 *     &sig_expr_MAC1LINK_MAC1LINK,
 *     NULL,
 * };
 *
 * static const struct aspeed_sig_desc sig_descs_GPIOA0_GPIOA0[] = { };
 *
 * static const struct aspeed_sig_expr sig_expr_GPIOA0_GPIOA0 = {
 *     .signal = "GPIOA0",
 *     .function = "GPIOA0",
 *     .ndescs = ARRAY_SIZE(sig_descs_GPIOA0_GPIOA0),
 *     .descs = &(sig_descs_GPIOA0_GPIOA0)[0],
 * };
 *
 * static const struct aspeed_sig_expr *sig_exprs_GPIOA0_GPIOA0[] = {
 *     &sig_expr_GPIOA0_GPIOA0,
 *     NULL
 * };
 *
 * static const struct aspeed_sig_expr **pin_exprs_0[] = {
 *     sig_exprs_MAC1LINK_MAC1LINK,
 *     sig_exprs_GPIOA0_GPIOA0,
 *     NULL
 * };
 *
 * static const struct aspeed_pin_desc pin_0 = { "0", (&pin_exprs_0[0]) };
 * static const int group_pins_MAC1LINK[] = { 0 };
 * static const char *func_groups_MAC1LINK[] = { "MAC1LINK" };
 *
 * static struct pinctrl_pin_desc aspeed_g4_pins[] = {
 *     [0] = { .number = 0, .name = "D6", .drv_data = &pin_0 },
 * };
 *
 * static const struct aspeed_pin_group aspeed_g4_groups[] = {
 *     {
 *         .name = "MAC1LINK",
 *         .pins = &(group_pins_MAC1LINK)[0],
 *         .npins = ARRAY_SIZE(group_pins_MAC1LINK),
 *     },
 * };
 *
 * static const struct aspeed_pin_function aspeed_g4_functions[] = {
 *     {
 *         .name = "MAC1LINK",
 *         .groups = &func_groups_MAC1LINK[0],
 *         .ngroups = ARRAY_SIZE(func_groups_MAC1LINK),
 *     },
 * };
 * ```
 *
 * At the end of the day much of the above code is compressed into the
 * following two lines:
 *
 * ```
 * #define D6 0
 * SSSF_PIN_DECL(D6, GPIOA0, MAC1LINK, SIG_DESC_SET(SCU80, 0));
 * ```
 *
 * The two examples below show just the differences from the example above.
 *
 * Ball E18 demonstrates a function, EXTRST, that requires multiple descriptors
 * be set for it to be muxed:
 *
 * ```
 * static const struct aspeed_sig_desc sig_descs_EXTRST_EXTRST[] = {
 *     {
 *         .ip = ASPEED_IP_SCU,
 *         .reg = 0x3C,
 *         .mask = BIT(3),
 *         .enable = 1,
 *         .disable = 0
 *     },
 *     {
 *         .ip = ASPEED_IP_SCU,
 *         .reg = 0x80,
 *         .mask = BIT(15),
 *         .enable = 1,
 *         .disable = 0
 *     },
 *     {
 *         .ip = ASPEED_IP_SCU,
 *         .reg = 0x90,
 *         .mask = BIT(31),
 *         .enable = 0,
 *         .disable = 1
 *     },
 * };
 *
 * static const struct aspeed_sig_expr sig_expr_EXTRST_EXTRST = {
 *     .signal = "EXTRST",
 *     .function = "EXTRST",
 *     .ndescs = ARRAY_SIZE(sig_descs_EXTRST_EXTRST),
 *     .descs = &(sig_descs_EXTRST_EXTRST)[0],
 * };
 * ...
 * ```
 *
 * For ball E19, we have multiple functions enabling a single signal, LPCRST#.
 * The data structures look like:
 *
 * static const struct aspeed_sig_desc sig_descs_LPCRST_LPCRST[] = {
 *     {
 *         .ip = ASPEED_IP_SCU,
 *         .reg = 0x80,
 *         .mask = BIT(12),
 *         .enable = 1,
 *         .disable = 0
 *     },
 * };
 *
 * static const struct aspeed_sig_expr sig_expr_LPCRST_LPCRST = {
 *     .signal = "LPCRST",
 *     .function = "LPCRST",
 *     .ndescs = ARRAY_SIZE(sig_descs_LPCRST_LPCRST),
 *     .descs = &(sig_descs_LPCRST_LPCRST)[0],
 * };
 *
 * static const struct aspeed_sig_desc sig_descs_LPCRST_LPCRSTS[] = {
 *     {
 *         .ip = ASPEED_IP_SCU,
 *         .reg = 0x70,
 *         .mask = BIT(14),
 *         .enable = 1,
 *         .disable = 0
 *     },
 * };
 *
 * static const struct aspeed_sig_expr sig_expr_LPCRST_LPCRSTS = {
 *     .signal = "LPCRST",
 *     .function = "LPCRSTS",
 *     .ndescs = ARRAY_SIZE(sig_descs_LPCRST_LPCRSTS),
 *     .descs = &(sig_descs_LPCRST_LPCRSTS)[0],
 * };
 *
 * static const struct aspeed_sig_expr *sig_exprs_LPCRST_LPCRST[] = {
 *     &sig_expr_LPCRST_LPCRST,
 *     &sig_expr_LPCRST_LPCRSTS,
 *     NULL,
 * };
 * ...
 * ```
 *
 * Both expressions listed in the sig_exprs_LPCRST_LPCRST array need to be set
 * to disabled for the associated GPIO to be muxed.
 *
 */

#define ASPEED_IP_SCU		0
#define ASPEED_IP_GFX		1
#define ASPEED_IP_LPC		2
#define ASPEED_NR_PINMUX_IPS	3

 /**
  * A signal descriptor, which describes the register, bits and the
  * enable/disable values that should be compared or written.
  *
  * @ip: The IP block identifier, used as an index into the regmap array in
  *      struct aspeed_pinctrl_data
  * @reg: The register offset with respect to the base address of the IP block
  * @mask: The mask to apply to the register. The lowest set bit of the mask is
  *        used to derive the shift value.
  * @enable: The value that enables the function. Value should be in the LSBs,
  *          not at the position of the mask.
  * @disable: The value that disables the function. Value should be in the
  *           LSBs, not at the position of the mask.
  */
struct aspeed_sig_desc {
	unsigned int ip;
	unsigned int reg;
	u32 mask;
	u32 enable;
	u32 disable;
};

/**
 * Describes a signal expression. The expression is evaluated by ANDing the
 * evaluation of the descriptors.
 *
 * @signal: The signal name for the priority level on the pin. If the signal
 *          type is GPIO, then the signal name must begin with the string
 *          "GPIO", e.g. GPIOA0, GPIOT4 etc.
 * @function: The name of the function the signal participates in for the
 *            associated expression
 * @ndescs: The number of signal descriptors in the expression
 * @descs: Pointer to an array of signal descriptors that comprise the
 *         function expression
 */
struct aspeed_sig_expr {
	const char *signal;
	const char *function;
	int ndescs;
	const struct aspeed_sig_desc *descs;
};

/**
 * A struct capturing the list of expressions enabling signals at each priority
 * for a given pin. The signal configuration for a priority level is evaluated
 * by ORing the evaluation of the signal expressions in the respective
 * priority's list.
 *
 * @name: A name for the pin
 * @prios: A pointer to an array of expression list pointers
 *
 */
struct aspeed_pin_desc {
	const char *name;
	const struct aspeed_sig_expr ***prios;
};

/* Macro hell */

#define SIG_DESC_IP_BIT(ip, reg, idx, val) \
	{ ip, reg, BIT_MASK(idx), val, (((val) + 1) & 1) }

/**
 * Short-hand macro for describing an SCU descriptor enabled by the state of
 * one bit. The disable value is derived.
 *
 * @reg: The signal's associated register, offset from base
 * @idx: The signal's bit index in the register
 * @val: The value (0 or 1) that enables the function
 */
#define SIG_DESC_BIT(reg, idx, val) \
	SIG_DESC_IP_BIT(ASPEED_IP_SCU, reg, idx, val)

#define SIG_DESC_IP_SET(ip, reg, idx) SIG_DESC_IP_BIT(ip, reg, idx, 1)

/**
 * A further short-hand macro expanding to an SCU descriptor enabled by a set
 * bit.
 *
 * @reg: The register, offset from base
 * @idx: The bit index in the register
 */
#define SIG_DESC_SET(reg, idx) SIG_DESC_IP_BIT(ASPEED_IP_SCU, reg, idx, 1)
#define SIG_DESC_CLEAR(reg, idx) { ASPEED_IP_SCU, reg, BIT_MASK(idx), 0, 0 }

#define SIG_DESC_LIST_SYM(sig, group) sig_descs_ ## sig ## _ ## group
#define SIG_DESC_LIST_DECL(sig, group, ...) \
	static const struct aspeed_sig_desc SIG_DESC_LIST_SYM(sig, group)[] = \
		{ __VA_ARGS__ }

#define SIG_EXPR_SYM(sig, group) sig_expr_ ## sig ## _ ## group
#define SIG_EXPR_DECL_(sig, group, func) \
	static const struct aspeed_sig_expr SIG_EXPR_SYM(sig, group) = \
	{ \
		.signal = #sig, \
		.function = #func, \
		.ndescs = ARRAY_SIZE(SIG_DESC_LIST_SYM(sig, group)), \
		.descs = &(SIG_DESC_LIST_SYM(sig, group))[0], \
	}

/**
 * Declare a signal expression.
 *
 * @sig: A macro symbol name for the signal (is subjected to stringification
 *        and token pasting)
 * @func: The function in which the signal is participating
 * @...: Signal descriptors that define the signal expression
 *
 * For example, the following declares the ROMD8 signal for the ROM16 function:
 *
 *     SIG_EXPR_DECL(ROMD8, ROM16, ROM16, SIG_DESC_SET(SCU90, 6));
 *
 * And with multiple signal descriptors:
 *
 *     SIG_EXPR_DECL(ROMD8, ROM16S, ROM16S, SIG_DESC_SET(HW_STRAP1, 4),
 *              { HW_STRAP1, GENMASK(1, 0), 0, 0 });
 */
#define SIG_EXPR_DECL(sig, group, func, ...) \
	SIG_DESC_LIST_DECL(sig, group, __VA_ARGS__); \
	SIG_EXPR_DECL_(sig, group, func)

/**
 * Declare a pointer to a signal expression
 *
 * @sig: The macro symbol name for the signal (subjected to token pasting)
 * @func: The macro symbol name for the function (subjected to token pasting)
 */
#define SIG_EXPR_PTR(sig, group) (&SIG_EXPR_SYM(sig, group))

#define SIG_EXPR_LIST_SYM(sig, group) sig_exprs_ ## sig ## _ ## group

/**
 * Declare a signal expression list for reference in a struct aspeed_pin_prio.
 *
 * @sig: A macro symbol name for the signal (is subjected to token pasting)
 * @...: Signal expression structure pointers (use SIG_EXPR_PTR())
 *
 * For example, the 16-bit ROM bus can be enabled by one of two possible signal
 * expressions:
 *
 *     SIG_EXPR_DECL(ROMD8, ROM16, ROM16, SIG_DESC_SET(SCU90, 6));
 *     SIG_EXPR_DECL(ROMD8, ROM16S, ROM16S, SIG_DESC_SET(HW_STRAP1, 4),
 *              { HW_STRAP1, GENMASK(1, 0), 0, 0 });
 *     SIG_EXPR_LIST_DECL(ROMD8, SIG_EXPR_PTR(ROMD8, ROM16),
 *              SIG_EXPR_PTR(ROMD8, ROM16S));
 */
#define SIG_EXPR_LIST_DECL(sig, group, ...) \
	static const struct aspeed_sig_expr *SIG_EXPR_LIST_SYM(sig, group)[] =\
		{ __VA_ARGS__, NULL }

#define stringify(x) #x
#define istringify(x) stringify(x)

/**
 * Create an expression symbol alias from (signal, group) to (pin, signal).
 *
 * @pin: The pin number
 * @sig: The signal name
 * @group: The name of the group of which the pin is a member that is
 *         associated with the function's signal
 *
 * Using an alias in this way enables detection of copy/paste errors (defining
 * the signal for a group multiple times) whilst enabling multiple pin groups
 * to exist for a signal without intrusive side-effects on defining the list of
 * signals available on a pin.
 */
#define SIG_EXPR_LIST_ALIAS(pin, sig, group) \
	static const struct aspeed_sig_expr *\
		SIG_EXPR_LIST_SYM(pin, sig)[ARRAY_SIZE(SIG_EXPR_LIST_SYM(sig, group))] \
		__attribute__((alias(istringify(SIG_EXPR_LIST_SYM(sig, group)))))

/**
 * A short-hand macro for declaring a function expression and an expression
 * list with a single expression (SE) and a single group (SG) of pins.
 *
 * @pin: The pin the signal will be routed to
 * @sig: The signal that will be routed to the pin for the function
 * @func: A macro symbol name for the function
 * @...: Function descriptors that define the function expression
 *
 * For example, signal NCTS6 participates in its own function with one group:
 *
 *     SIG_EXPR_LIST_DECL_SINGLE(A18, NCTS6, NCTS6, SIG_DESC_SET(SCU90, 7));
 */
#define SIG_EXPR_LIST_DECL_SESG(pin, sig, func, ...) \
	SIG_DESC_LIST_DECL(sig, func, __VA_ARGS__); \
	SIG_EXPR_DECL_(sig, func, func); \
	SIG_EXPR_LIST_DECL(sig, func, SIG_EXPR_PTR(sig, func)); \
	SIG_EXPR_LIST_ALIAS(pin, sig, func)

/**
 * Similar to the above, but for pins with a single expression (SE) and
 * multiple groups (MG) of pins.
 *
 * @pin: The pin the signal will be routed to
 * @sig: The signal that will be routed to the pin for the function
 * @group: The name of the function's pin group in which the pin participates
 * @func: A macro symbol name for the function
 * @...: Function descriptors that define the function expression
 */
#define SIG_EXPR_LIST_DECL_SEMG(pin, sig, group, func, ...) \
	SIG_DESC_LIST_DECL(sig, group, __VA_ARGS__); \
	SIG_EXPR_DECL_(sig, group, func); \
	SIG_EXPR_LIST_DECL(sig, group, SIG_EXPR_PTR(sig, group)); \
	SIG_EXPR_LIST_ALIAS(pin, sig, group)

/**
 * Similar to the above, but for pins with a dual expressions (DE) and
 * and a single group (SG) of pins.
 *
 * @pin: The pin the signal will be routed to
 * @sig: The signal that will be routed to the pin for the function
 * @group: The name of the function's pin group in which the pin participates
 * @func: A macro symbol name for the function
 * @...: Function descriptors that define the function expression
 */
#define SIG_EXPR_LIST_DECL_DESG(pin, sig, f0, f1) \
	SIG_EXPR_LIST_DECL(sig, f0, \
			   SIG_EXPR_PTR(sig, f0), \
			   SIG_EXPR_PTR(sig, f1)); \
	SIG_EXPR_LIST_ALIAS(pin, sig, f0)

#define SIG_EXPR_LIST_PTR(sig, group) SIG_EXPR_LIST_SYM(sig, group)

#define PIN_EXPRS_SYM(pin) pin_exprs_ ## pin
#define PIN_EXPRS_PTR(pin) (&PIN_EXPRS_SYM(pin)[0])
#define PIN_SYM(pin) pin_ ## pin

#define PIN_DECL_(pin, ...) \
	static const struct aspeed_sig_expr **PIN_EXPRS_SYM(pin)[] = \
		{ __VA_ARGS__, NULL }; \
	static const struct aspeed_pin_desc PIN_SYM(pin) = \
		{ #pin, PIN_EXPRS_PTR(pin) }

/**
 * Declare a single signal pin
 *
 * @pin: The pin number
 * @other: Macro name for "other" functionality (subjected to stringification)
 * @sig: Macro name for the signal (subjected to stringification)
 *
 * For example:
 *
 *     #define E3 80
 *     SIG_EXPR_LIST_DECL_SINGLE(SCL5, I2C5, I2C5_DESC);
 *     PIN_DECL_1(E3, GPIOK0, SCL5);
 */
#define PIN_DECL_1(pin, other, sig) \
	SIG_EXPR_LIST_DECL_SESG(pin, other, other); \
	PIN_DECL_(pin, SIG_EXPR_LIST_PTR(pin, sig), \
		  SIG_EXPR_LIST_PTR(pin, other))

/**
 * Single signal, single function pin declaration
 *
 * @pin: The pin number
 * @other: Macro name for "other" functionality (subjected to stringification)
 * @sig: Macro name for the signal (subjected to stringification)
 * @...: Signal descriptors that define the function expression
 *
 * For example:
 *
 *    SSSF_PIN_DECL(A4, GPIOA2, TIMER3, SIG_DESC_SET(SCU80, 2));
 */
#define SSSF_PIN_DECL(pin, other, sig, ...) \
	SIG_EXPR_LIST_DECL_SESG(pin, sig, sig, __VA_ARGS__); \
	SIG_EXPR_LIST_DECL_SESG(pin, other, other); \
	PIN_DECL_(pin, SIG_EXPR_LIST_PTR(pin, sig), \
		  SIG_EXPR_LIST_PTR(pin, other)); \
	FUNC_GROUP_DECL(sig, pin)
/**
 * Declare a two-signal pin
 *
 * @pin: The pin number
 * @other: Macro name for "other" functionality (subjected to stringification)
 * @high: Macro name for the highest priority signal functions
 * @low: Macro name for the low signal functions
 *
 * For example:
 *
 *     #define A8 56
 *     SIG_EXPR_DECL(ROMD8, ROM16, SIG_DESC_SET(SCU90, 6));
 *     SIG_EXPR_DECL(ROMD8, ROM16S, SIG_DESC_SET(HW_STRAP1, 4),
 *              { HW_STRAP1, GENMASK(1, 0), 0, 0 });
 *     SIG_EXPR_LIST_DECL(ROMD8, SIG_EXPR_PTR(ROMD8, ROM16),
 *              SIG_EXPR_PTR(ROMD8, ROM16S));
 *     SIG_EXPR_LIST_DECL_SINGLE(NCTS6, NCTS6, SIG_DESC_SET(SCU90, 7));
 *     PIN_DECL_2(A8, GPIOH0, ROMD8, NCTS6);
 */
#define PIN_DECL_2(pin, other, high, low) \
	SIG_EXPR_LIST_DECL_SESG(pin, other, other); \
	PIN_DECL_(pin, \
			SIG_EXPR_LIST_PTR(pin, high), \
			SIG_EXPR_LIST_PTR(pin, low), \
			SIG_EXPR_LIST_PTR(pin, other))

#define PIN_DECL_3(pin, other, high, medium, low) \
	SIG_EXPR_LIST_DECL_SESG(pin, other, other); \
	PIN_DECL_(pin, \
			SIG_EXPR_LIST_PTR(pin, high), \
			SIG_EXPR_LIST_PTR(pin, medium), \
			SIG_EXPR_LIST_PTR(pin, low), \
			SIG_EXPR_LIST_PTR(pin, other))

#define GROUP_SYM(group) group_pins_ ## group
#define GROUP_DECL(group, ...) \
	static const int GROUP_SYM(group)[] = { __VA_ARGS__ }

#define FUNC_SYM(func) func_groups_ ## func
#define FUNC_DECL_(func, ...) \
	static const char *FUNC_SYM(func)[] = { __VA_ARGS__ }

#define FUNC_DECL_1(func, group) FUNC_DECL_(func, #group)
#define FUNC_DECL_2(func, one, two) FUNC_DECL_(func, #one, #two)
#define FUNC_DECL_3(func, one, two, three) FUNC_DECL_(func, #one, #two, #three)

#define FUNC_GROUP_DECL(func, ...) \
	GROUP_DECL(func, __VA_ARGS__); \
	FUNC_DECL_(func, #func)


#define GPIO_PIN_DECL(pin, gpio) \
	SIG_EXPR_LIST_DECL_SESG(pin, gpio, gpio); \
	PIN_DECL_(pin, SIG_EXPR_LIST_PTR(pin, gpio))

struct aspeed_pin_group {
	const char *name;
	const unsigned int *pins;
	const unsigned int npins;
};

#define ASPEED_PINCTRL_GROUP(name_) { \
	.name = #name_, \
	.pins = &(GROUP_SYM(name_))[0], \
	.npins = ARRAY_SIZE(GROUP_SYM(name_)), \
}

struct aspeed_pin_function {
	const char *name;
	const char *const *groups;
	unsigned int ngroups;
};

#define ASPEED_PINCTRL_FUNC(name_, ...) { \
	.name = #name_, \
	.groups = &FUNC_SYM(name_)[0], \
	.ngroups = ARRAY_SIZE(FUNC_SYM(name_)), \
}

struct aspeed_pinmux_data;

struct aspeed_pinmux_ops {
	int (*eval)(struct aspeed_pinmux_data *ctx,
		    const struct aspeed_sig_expr *expr, bool enabled);
	int (*set)(struct aspeed_pinmux_data *ctx,
		   const struct aspeed_sig_expr *expr, bool enabled);
};

struct aspeed_pinmux_data {
	struct device *dev;
	struct regmap *maps[ASPEED_NR_PINMUX_IPS];

	const struct aspeed_pinmux_ops *ops;

	const struct aspeed_pin_group *groups;
	const unsigned int ngroups;

	const struct aspeed_pin_function *functions;
	const unsigned int nfunctions;
};

int aspeed_sig_desc_eval(const struct aspeed_sig_desc *desc, bool enabled,
			 struct regmap *map);

int aspeed_sig_expr_eval(struct aspeed_pinmux_data *ctx,
			 const struct aspeed_sig_expr *expr, bool enabled);

static inline int aspeed_sig_expr_set(struct aspeed_pinmux_data *ctx,
				      const struct aspeed_sig_expr *expr,
				      bool enabled)
{
	return ctx->ops->set(ctx, expr, enabled);
}

#endif /* ASPEED_PINMUX_H */